PlaySudoku.us
Medium · Puzzle #561
3
1
6
5
8
3
5
1
5
4
3
9
1
2
6
7
4
3
1
5
7
6
7
3
1
2
8
9
3
6
8
"Play the opening like a book, the middlegame like a magician, and the endgame like a machine." — Rudolf Spielmann
"Play the opening like a book, the middlegame like a magician, and the endgame like a machine." — Rudolf Spielmann
In combinatorics, the pattern formed by Sudoku clue cells is studied as a problem in 'hitting sets' and transversals.
In combinatorics, the pattern formed by Sudoku clue cells is studied as a problem in 'hitting sets' and transversals.